Study on Channel Access Mechanism of IEEE802.15.4 MAC Layer;

A channel access-ba.

This paper firstly expounded the necessities of using clustering network structure in Ad Hoc networ k, then discussed applications and related issues of clustering network structu re in Ad Hoc network from various aspects, including cluster based routing, hierarchical mobility management, resource assignments and channel access schemes, flooding broadcast schemes, power control an.

Research on configuration method for access channel in CDMA system;

This article explains the structure and operation of CDMA access channel, introduces concepts to estimate and optimize CDMA IS 95 access channel capacity.

Since it is very difficult to compute the sum rates capacity of Gaussian MIMO broadcast channels directly by using dirty paper coding approach,an iterative water-filling algorithm is proposed to obtain the sum capacity bound for multi-access channel and a suboptimal transmission policy to achieve the capacity bound is derived from the algorithm.

The capacity region with average power constraints of MIMO fading multi-access channels based on minimum rate requirements is analyzed and the optimal power allocation strategy is suggested.